Wellcome Trust Research Round-up: 12.01.2015

Our fortnightly round-up of research news from the Wellcome Trust community…

Bacteria in the human gut have evolved to utilise yeasts

Saccharomyces cerevisiae or Baker’s yeast, comonly used in brewing beer, baking and winemaking. Credit Dr. Wei-Feng Xue, Wellcome Images

Research from Newcastle University and the University of Michigan suggests that microbes in our digestive tract have evolved to break down a complex carbohydrate that makes up the yeast cell wall, allowing the digestion of yeast in food.

This Wellcome Trust supported study, published last Thursday in Nature, identified the complex machinery involved in metabolising the carbohydrate, called alpha-‘Mannan’, in a bacterium called Bacteroides thetaiotaomicron. Genetic analysis suggests that this is capability has evolved in the community of bacteria that live in our gut, at least twice.

Mannans, derived from the yeast cell wall, are a component in our diet from fermented foods including bread, beer, wine and soy sauce. It is thought that these foods have been in the human diet for at least 7000 years.

The international research team say the discovery of this process could accelerate the development of prebiotic medicines, which promote the growth of bacteria that contribute to our well-being, to help people suffering from bowel problems and autoimmune diseases.

Professor Harry Gilbert, a Wellcome Trust Senior Investigator and the senior author of the paper explained, “There’s a lot of interest in developing prebiotics. The more you understand about how complex glycans are degraded the more you can think about developing sophisticated prebiotics that target the growth or specific beneficial bacteria.”

Primordial egg and sperm cells created by researchers

Egg and sperm cell. Credit: Spike Walker, Wellcome Images

Scientists at the University of Cambridge working with the Weizmann Institute have created precursors to human egg and sperm cells using human embryonic stem cells. Although this has already been done using rodent stem cells, the study, published on the 24th of December in the journal Cell, is the first time this has been achieved efficiently using human stem cells.

Dr Naoko Irie from the Wellcome Trust/Cancer Research UK Gurdon Institute at the University of Cambridge and colleagues found that a gene known as SOX17 is critical for directing human stem cells to become primordial germ cells, which later give rise to egg and sperm cells. The mouse equivalent of this gene is not involved in the process, suggesting a key difference between mouse and human development.

“The creation of primordial germ cells is one of the earliest events during early mammalian development,” says Dr Irie. “It’s a stage we’ve managed to recreate using stem cells from mice and rats, but until now few researchers have done this systematically using human stem cells. It has highlighted important differences between embryo development in humans and rodents that may mean findings in mice and rats may not be directly extrapolated to humans.”

This work was funded by Wellcome Trust and BIRAX (the Britain Israel Research and Academic Exchange Partnership). You can read more about the research here.

Research findings suggest how skin damage can lead to tumour formation

Watercolour drawing illustrating the appearance of the disease known as epidermolysis bullosa. The patient was a man of 60 who was suffering from a malignant tumour in the abdomen. The eruption began on the arms and legs, lasted for about six weeks then disappeared. Drawing shows the patient’s arm.
Credit: St Bartholomew’s Hospital Archives & Museum, Wellcome Images, Wellcome Images

Researchers at King’s College London have identified a new mechanism by which skin damage triggers the formation of tumours. The study, published last Friday in Nature Communications, could have important therapeutic implications for patients suffering with chronic ulcers or skin blistering diseases.

The research, carried out in mice, highlights an innate sensing of bacteria by immune cells in the formation of skin tumours. This molecular process could tip the balance between normal wound repair and tumour formation in some patients, according to researchers.

Although an association between tissue damage, chronic inflammation and cancer is well established, this study –supported by the Medical Research Council and the Wellcome Trust – is the first to demonstrate that bacteria present on the skin can contribute to the development of skin tumours.

A research team led by Professor Fiona Watt, Director of the Centre for Stem Cells and Regenerative Medicine at King’s College London found that when mice with chronic skin inflammation are wounded they develop tumours at the wound site. They discovered that the underlying signalling mechanism involves a bacterial protein, flagellin, which is recognised by a receptor on the surface of the immune cells.

Although the direct relevance to human tumours is yet to be tested, researchers have shown that a protein called HMGB1 – found to be highly expressed in mice with chronic skin inflammation – is increased in human patients with a blistering skin condition called Epidermolysis bullosa.

In other news…

Congratulations are in order for Wellcome Trust Screenwriting fellow Jonathan Glazer, who was nominated for the BAFTA Best British Film award. Have a look at the nominations here.

A novel breast cancer gene has been found by Wellcome Trust supported researchers from the Sanger Institute and University of Cambridge.

Applications are open for the 2016-18 £1 million Hub Award for interdisciplinary health-related projects. If you’re interested in finding out more, register for our open days in February and March, to see the space, meet current award-holders Hubbub group and talk to Trust staff.